Pyrazole-assisted tetranuclear microporous polyoxovanadates(III) (POVs) (NH₄)₂K₂[V₄(μ₂-OH)₄(ox)₄(pz)₄]·9H₂O (1, ox = oxalate and pz = pyrazole) and (NH₄)₂Na₂[V₄(μ₂-OH)₄(ox)₄(4-mpz)₄]·7H₂O (2, 4-mpz = 4-methylpyrazole) have been constructed in reduced media, along with their triazole neutral hexa- and octanuclear products K₂[V₆(μ₂-OH)₆(ox)₆(Hdatrz)₆]Cl₂·29.5H₂O (3) and [V₈(μ₂-OH)₈(SO₃)₈(Hdatrz)₈]·38H₂O (4, Hdatrz = 1H-1,2,4-triazole-3,5-diamine) successively. Both polyanionic structures of 1 and 2 share similar inorganic building blocks that consist of regular {V₄(μ₂-OH)₄} skeletons with an inner diameter of 2.8 Å, while a paddle wheel-shaped cluster 3 contains a {V₆(μ₂-OH)₆} skeleton with two chlorides encapsulated around the center of the ring, occupying a hole of 3.7 Å. An interesting isolated intrinsic polyoxometalate-based metal–organic framework (POMOF) 4 exists as an octanuclear petaloid-like skeleton {V₈(μ₂-OH)₈(SO₃)₈} with an inner diameter of 5.2 Å. Bond valence sum calculations manifest that all V ions have severely reduced +3 oxidation states in 1–4, which are supported by charge balance, structural and magnetic data. Moreover, gas adsorptions indicate that 1, 2 and 4 can adsorb CO₂ and O₂ more favorably than N₂, CH₄ and H₂ gases. Compared with 1 and 2, due to the functionalization of microchannels with Lewis base amino and hydroxy groups and uncoordinated azolate N-donors inside POMOF 4, it should have notable affinities toward CO₂ adsorption.

中文翻译：

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用于气体吸附的常规四核、六核和八核微孔多钒酸盐（III）的连续构建

吡唑辅助四核微孔多钒酸盐( III ) (POVs) (NH ₄ ) ₂ K ₂ [V ₄ (μ ₂ -OH) ₄ (ox) ₄ (pz) ₄ ]·9H ₂ O ( 1 , ox = 草酸盐和pz =吡唑)和(NH ₄ ) ₂ Na ₂ [V ₄ (μ ₂ -OH) ₄ (ox) ₄ (4-mpz) ₄ ]·7H ₂ O ( 2, 4-mpz = 4-methylpyrazole) 及其三唑中性六核和八核产物 K ₂ [V ₆ (μ ₂ -OH) ₆ (ox) ₆ (Hdatrz) ₆ ]Cl ₂ · 29.5H ₂ O ( 3 ) 和[V ₈ (μ ₂ -OH) ₈ (SO ₃ ) ₈ (Hdatrz) ₈ ]·38H ₂ O ( 4 , Hdatrz = 1 H -1,2,4 -triazole-3, 5-二胺）依次。1和2的聚阴离子结构共享相似的无机结构单元，由内径为 2.8 Å的规则 {V ₄ (μ ₂ -OH) ₄ } 骨架组成，而桨轮状簇3包含 {V ₆ (μ ₂ -OH) ₆ }在环中心周围有两个氯化物的骨架，占据了一个 3.7 Å 的孔。一个有趣的孤立的本征多金属氧酸盐基金属有机骨架 (POMOF) 4作为八核花瓣状骨架 {V ₈ (μ ₂ -OH) ₈ (SO ₃ ) _8存在} 内径为 5.2 Å。键合价和计算表明，所有 V 离子在1-4中都严重降低了 +3 氧化态，这得到了电荷平衡、结构和磁性数据的支持。此外，气体吸附表明1、2和4比N 2、CH ₄和H ₂气体_更能吸附CO ₂和O _{2 。}与1和2相比，由于微通道具有路易斯碱氨基和羟基的功能化以及 POMOF 4内部未配位的氮杂氮供体，它应该对 CO 具有显着的亲和力₂吸附。